Is a continued stockpiling effort worth Doug McDermott?
Other rebuilding teams often use their cap space to sign good players to value contracts, and that gives them the option to trade them later for assets. The Spurs did just that with Bryn Forbes, shipping him to Denver in a deal that netted them a future second, and they could theoretically do the same with McDermott.
The asking price would definitely be higher, with McDermott being worth at least a 1st round pick. However, considering that the Spurs have already acquired three future firsts, they may or may not be interested in adding another. On one hand, McDermott is currently starting for the Spurs and they don’t have an immediate replacement for him.
On the other hand, a 1st round pick is still incredibly valuable, especially with the team's track record in drafts. Thus, the decision to move him could ultimately come down to what happens in the 2022 NBA Draft. San Antonio has three picks in the top 20, and could conceivably trade up to take Jabari Smith or Paolo Banchero. Or they could stay put and potentially be in a position to select Keegan Murray.
They're considered to be the three best power forwards in the draft, and each is good enough to start for San Antonio next season. Were the Spurs to select one of them, then that would push McDermott to the bench, making him more expendable.